Neurofibromatosis type 1 (NF1) is a
genetic disease characterized by neoplastic and nonneoplastic disorders involving tissues of neuroectodermal and mesenchymal origin. The mainly involved districts are skin, the central nervous system, and eye and there is a wide range of severity of clinical presentations. Abdominal manifestations of NF1 include five kinds of
tumors: neurogenic
tumors (
neurofibromas,
malignant peripheral nerve sheath tumors [MPNSTs], and
ganglioneuromas);
neuroendocrine tumors (
pheochromocytomas and
carcinoids); nonneurogenic
gastrointestinal stromal tumors (GISTs); embryonal
tumors; and miscellaneous. The present experience depends on the participation in the National Project for Diagnosis and Treatment of
Rare Diseases. In the group of patients with a diagnosis of
von Recklinghausen disease, 10 patients underwent surgical treatment for gastrointestinal and retroperitoneal
tumors associated with NF1. Three patients underwent
adrenalectomy for
pheochromocytoma (in one case associated with jejunal wall
neurofibroma); two patients were found to be affected by
MPNST (recurrent and unresectable in one case). One patient was affected by giant gastric GIST and jejunal
neurofibroma; two patients were affected by extraperitoneal
neurofibroma (pararenal and pararectal position); one patient was affected by giant
colic neurofibroma and one patient was affected by retroperitoneal bilateral
plexiform neurofibromas. Early diagnosis of these abdominal manifestations is very important because of the risk of
malignancy, organic complications (such as
pheochromocytoma), or hemorrhagic-obstructive complications such as in case of
tumors of the gastrointestinal tract (GISTs and
neurofibromas). The importance of an annual clinical evaluation on the part of a multidisciplinary pool of clinicians in highly specialized centers allows early detection of complications and of neoplastic transformation. Genetic screening allows preclinical diagnosis with a sensibility of 95 per cent. Further studies are necessary to detect predictive factors of malignant
tumor development of severe clinical conditions.